Tag Archives: Refactor

Refactor conditionals by Decompose Conditional

Blog post series

This blog post is part of a series about legacy coderetreat and legacy code techniques you can apply during your work. Please click to see more sessions about legacy code.

Purpose

We often see code with conditionals that are hard to understand. The purpose of this technique is to make the code look readable by extracting a function with the condition. It will be easier to test the code if the condition is extracted and injected as a dependency.

This technique is useful when having good variable names is not enough to explain the condition. We can have some of the following reasons for wanting to extract a function with the condition:

The condition is duplicated in several parts of the class

The condition is duplicated along different classes

Test the condition in isolation, because of its complex nature

Test the code without understanding how the conditions work (inject conditions as stubs)

Refactor conditionals: Explain Variable

Blog post series

This blog post is part of a series about legacy coderetreat and legacy code techniques you can apply during your work. Please click to see more sessions about legacy code.

Purpose

When you try to read a code base that has many conditionals, often the problem is that the condition itself is very hard to understand. This technique improves the conditionals by making them clear and very easy to read. Read More →

Extract Class

Blog post series

This blog post is part of a series about legacy coderetreat and legacy code techniques you can apply during your work. Please click to see more sessions about legacy code.

Purpose

When working with existing code we need to look at the responsibilities of existing classes. If one class is too big, we need to extract new classes from that initial class. A class too big means that it’s not respecting the Single Responsibility Principle.

Extract Pure Functions

Blog post series

This blog post is part of a series about legacy coderetreat and legacy code techniques you can apply during your work. Please click to see more sessions about legacy code.

Purpose

We have some class that is very big. We want to divide the existing code into more methods and classes so that we have in the end some code that is easier to understand. If the methods are small, they are easy to change. In the same time the code would respect the Single Responsibility Principle. We optimize our software for changeability. In the following we will see how we can extract pure functions to achieve that.